title: The effects of progressive exercise on cardiovascular function in elite athletes: focus on oxidative stress.
abstract: Some side-effects of excessive physical training are ascribed to reactive oxygen species production. In this work we investigated the effects of progressively imposed maximal physical effort (levels I to V), using progressive maximal exercise test, on peripheral blood lactate, NO (through NO2-), superoxide anion (O2-) and methemoglobin (MetHb) in a group of 19 elite soccer players. Blood lactate (mmol/L) was increased (4.55, level V vs. resting level, 1.95). The basal production of NO2- was in the direct relation with O2 consumption. Significant increase (p<0.05) in O2- values at effort level I (4.18) as compared to the resting value (4.01), and the significant increase (p<0.01 or p<0.05) in the MetHb (%) was found between II (18.79) and III (19.63) or between II and IV (19.24) effort levels, respectively. The regression lines of NO2- and O2- crossed at the level of the respiratory compensation point (RC), suggesting that RC could be of a crucial importance not only in the anaerobic and aerobic metabolism but in mechanisms of signal transductions as well. The results could be of the theoretical interest and also useful in designing an athlete training strategy.
authors.affiliation: Department of Physiology, Faculty of Medicine, University of Kragujevac, Svetozara Markovica 69, P. P. 124, 34000 Kragujevac, Republic of Serbia. drvladakgbg@yahoo.com
authors.forename: Vladimir Lj
authors.initials: VLj
authors.lastname: Jakovljević
authors.forename: M
authors.initials: M
authors.lastname: Zlatković
authors.forename: D
authors.initials: D
authors.lastname: Cubrilo
authors.forename: I
authors.initials: I
authors.lastname: Pantić
authors.forename: D M
authors.initials: DM
authors.lastname: Djurić
mesh_terms: D056352:Athletes; D002320:Cardiovascular Physiological Phenomena; D005080:Exercise Test / Q000379:methods; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008706:Methemoglobin / Q000378:metabolism; D009569:Nitric Oxide / Q000097:blood; D018384:Oxidative Stress / Q000502:physiology*; D010101:Oxygen Consumption / Q000502:physiology; D010807:Physical Endurance / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology*; D012916:Soccer; D013481:Superoxides / Q000097:blood
chemical_list: D013481:Superoxides; D009569:Nitric Oxide; D019344:Lactic Acid; D008706:Methemoglobin